1. Field of the Invention
This invention relates to locking devices used for securing computer equipment and cassette tape decks, and more particularly, to a device for preventing unauthorized use of computer floppy disk drives or cassette tape decks.
2. Description of the Prior Art
The invention is an improvement on devices such as U.S. Pat. No. 4,856,304 by Jay S. Derman, U.S. Pat. No. 4,640,106 by Jay S. Derman and U.S. Pat. No. 4,131,001 by Raymond J. Gotto. U.S. Pat. No. 4,131,001 utilizes a cassette-shaped part for insertion in the cassette chamber opening. The rotation of a lock cylinder moves projecting arms and locking members against the inside chamber surfaces preventing removal of the locking device. U.S. Pat. No. 4,856,304 utilizes a transverse plastic block and a "T" shaped tongue piece of stainless steel. The tongue piece is inserted in a horizontal slot in the transverse block and the rearward projecting member of the assembly is inserted in the cassette chamber opening. When pulled by hand, a projecting ridge on the tongue piece bears against the inside edge of the chamber opening. A cylinder lock is rotated to engage a slot cut in the tongue piece, preventing the device from being removed.
U.S. Pat. No. 4,640,106 uses an assembly to cover the cassette door opening and a "U" shaped body bolt together with a threaded rod for insertion in the cassette chamber. A locking element located on the threaded rod is rotated in position by a cylinder lock to prevent removal of the device.
U.S. Pat. No. 4,856,304 is considered the most simple in construction. However, the tongue piece remains somewhat complex. It is also limited in its adjustment stops, using either slots for a cam lock or holes for a padlock.